视频图像高压缩比编码算法研究

提出了一种基于DCT变换的矢量自适应分类的全局矢量量化编码算法。为降低码矢的维数和计算复杂度，提高搜索速度和压缩比，将变换的DCT矢量自适应分类为平滑类、边缘类和纹理类，根据矢量的类别构造不同长度的变换矢量和根据矢量的类别分别采用改进的全局矢量量化算法进行相应的码书设计。为提高光照变化时相邻帧间矢量运动补偿的匹配率，在矢量构造中将DC系数单独进行编码。实验结果表明：该算法在信噪比和压缩比方面具有良好的视频压缩性能，比较适合于智能视频监控系统以及水下视频等光照随时间有较大变化的场合。

Study on Video Coding Algorithm with High Compression Ratio

This paper presents a global vector quantization(VQ) algorithm based on adaptive classified vectors in discrete cosine transform(DCT) domain.In order to reduce the dimension of vector and the computing time while increasing the searching speed and compression ratio,the DCT-transformed vectors are classified as smooth vector,or edge vector or texture vector adaptively,and the length of the vectors is determined according to their types of class,and the corresponding code-book is designed by using the modified VQ algorithm.Moreover,to improve the motion compensation rate for vectors between the consecutive frames in the case of illumination variation,the DCT coefficient is removed from the transformed vector and coded individually.Experimental results show that the proposed algorithm can provide good video coding performance in terms of compression ratio and PSNR,especially applying to the scenarios where the illumination has a great variation,such as intelligent video monitoring system and underwater video imagery.